Sam's Realization
by thewinchesterlifestyle
Summary: He has been forcing himself to stop touching his stomach around his family; from acknowledging that there is a life growing inside of him. Dean regularly covers his scent and doesn't bring any of his family back to his apartment. The same one he shares with his mate because Cas is his and he wants that for a little while longer. (Alpha!Cas/Omega!Dean)


**Disclaimer**: _If you recognize it then I don't own it._

**Pairing**: _Cas/Dean_

**Warnings**: _Omega!Dean, Alpha!Cas, Alpha!Sam, a/b/o dynamics, mpreg, Protective!Sam_

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He has been forcing himself to stop touching his stomach around his family; from acknowledging that there is a life growing inside of him. Dean regularly covers his scent and doesn't bring any of his family back to his apartment. The same one he shares with his mate because Cas is _his_ and he wants that for a little while longer. Just wants to put off what he knows are going to be disappointed looks that the oldest Winchester boy is an Omega and mated to an Alpha.

Dean doesn't expect the snowstorm to strand him with Sam nor how quickly the scent suppressants wear off. It only takes a few days of being locked in close quarters before it happens. He's standing in Sam's kitchen, cooking breakfast as he sings along under his breath, when a snarl comes from behind.

The Omega's entire body tenses as he slowly turns but Sam is standing right there. Taking in his scent and his eyes darken in fury. "Who is it? Who did this to you?" his voice is threatening and Dean swallows. Staring at his brother even as he backs into the counter a low sound escaping at the furious Alpha in front of him.

"Sam?" the eggs are going to burn but he puts a placating hand on his brother's shaking form. "Sammy. What are you talking about?" because it hasn't clicked yet. "What's wrong?"

But Sam isn't listening and he's still growling. Fury washing over his senses as he steps closer. Nose at the base of Dean's neck and breathing in. Trying to find the scent of the Alpha who took advantage of his brother. His Omega brother who had never shown any interest in taking a mate or having children.

Eyes flashing he steps away and starts towards the door. And Dean is rushing to catch up. "Sam! Hey Sam!" his words are ignored and Sam is shrugging on his coat. Mind already intent on finding the Alpha who did this to his brother and making them pay.

Watching his brother moving through the snow Dean pulls his cell out and dials up Cas, "Cas…I think my brother is looking for you." he doesn't bother to keep the worry out of his voice even as he starts to move around and collect his things.

"And?" the voice coming across the line is nonchalant. "It's about time I met some of your family." Cas's tone is still light and Dean pulls on his shoes. Reaches for his coat and the smell of burning eggs has him rushing to shut everything off in the kitchen.

"Dammit Cas. Sam is pissed." he yanks the door open and starts trudging through the snow to his car. Through the path that Sam had cleared earlier this morning before he'd come into the kitchen.

"That's fine with me." Cas sighs, "After we talk I can come over there to pick you up if your car is still stuck."

Dean stares at his car and the keys in his hands. "Sure Cas." he hangs up and starts the car. When it roars he life he lets out a sigh, "Good girl." comes out muttered as he waits for it to heat up and then backs out onto the road.

It's the longest drive of his life and when he gets there he races up the stairs. Taking them two at a time before moving down the hallway to their apartment door. His hand reaches out and he yanks the door open. Takes in the slight damage to the living room and feels his breathing hitch.

"Cas? _Cas_!" he doesn't stop the worry from bleeding into his voice and his heart is pounding in his ears. Everything is still and pressing close as he moves through the room looking for his mate.

Muffled noises down the hall have him moving once more and yanking the door open. Cas has Sam pinned down on the floor, pressing his knee into his back and holding his hands behind his back.

"This is not how I imagined meeting Dean's little brother." he sounds so reasonable and Dean slumps against the door frame. Regulates his breathing and when he looks over blue eyes are staring at him. Concern dancing in them. "Hello Dean."

"_Cas_." he breathes it out and takes a couple steps into the room, "Sammy." he swallows, "Cas will you get off my brother?" his heart is returning to normal and he can breathe again. Everything is snapping back into place and all he wants to do is bury his face against Cas. Breathe in his mate and know he's fine. That Sam didn't kill him and they're all ok.

"Of course." Cas releases Sam's wrists and climbs off of him easily. Rocking back on his heels and putting himself between the two brothers. The need to protect himself from the once violent and aggressive Alpha still at the front of his mind. Muscles tense and ready if the need should arise that he will have to put Sam back down. Protect his home and mate.

Sam rolled over and stared up at the blue eyed Alpha who was standing protectively in front of his brother. He sees Dean's worried face and how his brother takes a few steps forward to place his hand on Cas's shoulder. Leaning into the Alpha. Breathing _Cas_ in and relaxing against him. Green eyes bright and relieved as he finally looks around at Sam still sitting on the floor.

"Sam. This is my mate, Cas. Cas…this is my little brother Sam." he shakes his head as Sam gets to his feet. "Sammy…I'm going to have a baby." It comes out softly and he finally allows his hand to touch his belly. Wonder and pride obvious in his voice. Cas noticeably swells up at the words and his expression is that of a proud Alpha. An arm snakes out and drags Dean close as he presses his face into Dean's neck. Scenting him and sighing out. Blue eyes were bright as they turned back to regard the youngest Winchester.

"Pleased to meet you."

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**Prompt**:_ I have a prompt for Omega!Dean Wednesday if you're still interested? Um, Alpha!Cas and Dean mate secretly and Dean uses like, smell suppressants cause he doesn't want his family to know (maybe John treated him differently when he became an omega or something so he's embarrassed). But Alpha!Sam figures out Dean is pregnant somehow and goes 'super protective brother mode' and goes on a rampage to hunt the Alpha that took advantage of his brother... I'll leave how it ends up to you?_


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